Firstly I would like to say I have done a little bit of research but I am struggling to get a definitive answer, or perhaps im reading wrong or not read the right threads. Anyway, as per my other post about my high pitched screaming noise, I took the car back to the garage for diagnostics and they found that there was play in turbo bearing and wanted £700 to repair, (not replace) I have a few questions to ask you guys 1. Is my turbo a K03S? I'm pretty sure it is but I need confirmation 2. I'm going to attempt to replace the turbo my self once I've identified the turbo, It seems a fairly simple? job to do, 6 bolts and oil feed pipes. so - is it fairly simple? 3. What should be checked and or replaced whilst I've got good access 4. Is it a good idea to upgrade to the K04-015? as its a bolt on fitment with nothing extra required. Do you have any other suggestions, tips/advice for me. Any help is much appreciated Thanks in advance! Just for reference http://www.audi-sport.net/vb/a4-a4-...s/201867-high-pitched-scream-under-boost.html Edit - Reading on here, Bearings fail from Oil starvation or badly built turbo, I wouldn't of thought it would be a badly built turbo as it was running fine, no codes according to my fault reader. so my guess would be something has damaged the internals when I originally tried fitting the K&N cone filter or it may well be oil starvation. could be non related but I have got slight oil leak from Rocker cover gasket.